Many cameras, particularly one-time-use cameras, have single bladed impact shutters. This type of shutter has a shutter blade that pivots about a point offset from an exposure opening. The shutter blade has a first portion that covers an exposure aperture and a second portion, on the other side of the pivot point, that is struck to momentarily open the shutter. The shutter blade is biased closed by a biasing spring. The shutter blade, or a lever connected to the shutter blade, is struck by a fast moving lever, often referred to as a “high energy lever”. Some other impact shutters operate in a similar manner, but have more than one blade.
Energy is typically supplied to a high energy lever by one or more springs that arc biased (also referred to as “charged”) by a film transport mechanism during the advancing of a film frame. After biasing, the high energy lever is latched by another part. The latching is released by the shutter release. The location and operation of a high energy lever in a camera are, thus, constrained by required interactions with other camera components. Many cameras have high energy levers that pivot a lever arm about a center point to impact the shutter. Others have a high energy lever that slides to translate a portion of the high energy lever against the shutter.
High energy levers are subject to some competing constraints. Since high energy levers are fast-moving parts, weight has to be kept low. For simplicity, single part rather than multiple part high energy levers are desirable. On the other hand, the high energy lever needs to interact with both the film transport mechanism and the shutter. With simple cameras, there is typically a big separation between the shutter and the high energy lever. The shutter is near the lens at the forward end of a light baffle or lens barrel. The film transport is near the film near the opposite end of the baffle or barrel. The main portion of the high energy rotates or slides near the film transport mechanism and an arm or striker of the high energy lever extends forward to the shutter. If the baffle or barrel is long, then the arm is likewise long. U.S. Pat. No. 4,595,269 and Japanese patent publication JP 2-105127, published Apr. 17, 1990, both disclose cameras having long high energy levers. In both cases, the high energy levers are also stepped one or more times. These kinds of long high energy lever arms have a risk of bending during use, particularly when used at a relatively high ambient temperatures. This degrades the accuracy of shutter speeds and exposure times and can degrade the quality of pictures taken.
U.S. Pat. No. 3,672,280 discloses a camera having a retractable lens barrel. In the camera, an elongate operation arm extends forward from an operation plate. A release lever has a belt crank shape having two oppositely directed legs. The release lever extends backwards toward the operation plate. One of the legs of the release lever contacts the operation arm and is moved along the operation arm when the lens barrel is retracted. When a shutter button on the camera is pressed, the operation plate and operation arm move (the operation plate is spring biased opposing this movement), operating the release lever. These features are biased in the opposite direction from the biasing of a shutter driver for an impact shutter.
It would thus be desirable to have an improved camera in which the high energy lever has a reduced risk of bending.